Tiny Flex Extruder Bowden - 20mm spring

I wanted to use the [Tinyflex Bowden Extruder](http://www.thingiverse.com/thing:636178) to start playing around with flexible filament, but it was impossible for me to find the 30mm spring required, so I remixed it to use the 20mm spring that's widely available on almost any site that sells 3d printer parts.

For the hobbed gear, google "Hobb-Goblin 5mm/8mm ID Drive Gear" or get it [here](http://www.filastruder.com/products/hobb-goblin-5mm-id-drive-gear)